Invasion of Suruga

The Invasion of Suruga occurred in 1569 during the Sengoku period. During the 1560s, the powerful Imagawa, Takeda, and Hojo clans of the Kanto region formed a non-aggression pact, agreeing not to continue fighting for control of Kanto. However, Shingen Takeda, with assistance from Ieyasu Tokugawa, violated the pact by invading Suruga Province, the land of the Imagawa clan, so Yoshimoto Imagawa requested assistance from northern warlord Kenshin Uesugi. Kenshin decided to lead an army from Echigo Province to assist the Imagawa, and the two allied armies met in battle.

While the Uesugi army would attack the Tokugawa main camp - defended by Tadakatsu Honda - the Imagawa army would attack the Takeda main camp. The Uesugi succeeded in defeating Tadakatsu and then storming the Tokugawa main camp, routing Ieyasu. However, the Takeda launched a counterattack, and Nobuteru Sena, Masasada Asahina, and Ujimoto Katsurayama defected to the Takeda army. Kenshin's defeat of Mototada Torii led to Sadamitsu Suganuma arriving with Uesugi reinforcements, and the Uesugi went on to defeat the traitors. Nobuteru Sena and Ujimoto Katsurayama returned to the Imagawa army after Kenshin defeated Masasada Asahina, turning the tide of the battle. The Takeda general Yukimura Sanada attempted to launch a counterattack against the Imagawa main camp, and Kenshin was able to reach him before his sister Aya could. The Uesugi were able to repel the Sanada counterattack, and, to assist the Uesugi-Imagawa army, Ujiyasu Hojo arrived with aid, saying that he and Kenshin were the only fools in Japan who continued to honor alliances in the age of betrayal and war. Kenshin went on to assault the Takeda main camp, defeating Shingen and forcing his army to retreat.